This invention relates generally to refrigeration appliances, and, more particularly to, an apparatus and method for constructing refrigeration appliance cabinets.
Known refrigeration appliances, such as refrigerators, include a cabinet housing including an outer case and one or more inner liners therein that defines a fresh food compartment and a freezer compartment. The fresh food compartment and freezer compartments are closed by separate access doors hingedly attached to the case. A mullion extends across the front of a partition that separates the fresh food and freezer compartments in the liner and is attached to the outer case to reinforce the front of the outer case and preserve a pleasing aesthetic appearance of the refrigerator. Typically, the casing is fabricated from relatively thin sheet metal and includes a U-shaped shell to which a back and a bottom panel are attached to form an enclosure that contains the liner. A resin foam insulation medium is interposed between the casing and a plastic liner to insulate the refrigeration compartments of the refrigerator and also to increase structural rigidity and strength of the refrigerator cabinet. See for example, U.S. Pat. Nos. 4,822,117 and 4,632,470. A lower rail extends across the bottom of the cabinet and includes a grille providing access to a machinery compartment in the bottom of the refrigerator compartment.
While for some time refrigerator liners were installed into cabinets that were pre-fabricated with the foam, recent manufacturing efforts have been directed to foaming refrigerator cabinets after the liners have been inserted into the casing shell, a practice which has been found to reduce undesirable liner stress and associated cracking of the liner in use.
However, foaming of the cabinets after insertion of liners has proven problematic in other aspects. For example, once the liner is installed into the casing shell, access is severely restricted to attach the casing bottom panel to the shell, and conventional automated equipment to install the casing bottom panel cannot be used. While tooling and fixtures to install the casing bottom panel to the cabinet before foaming operations may be found, they may be employed only with increased manufacturing and assembly costs. In addition, difficulties in securing the casing bottom panel to the shell tend to result in undesirable foam leaks in foaming operations, especially in an area where the casing bottom panel is attached to the lower rail at the bottom of the refrigerator